Since polyolefin resins are degraded by light and thus cannot withstand long-term use, they are commonly used after being stabilized with an ultraviolet absorber and/or a hindered amine compound.
It is known that excellent weather resistance can be attained by combining a hindered amine compound and a benzoate compound and, for example, in Patent Documents 1 to 7, such a combination is shown to impart excellent weather resistance to automobile materials, fiber materials and agricultural films. In addition, it is also known to prepare a masterbatch of a hindered amine compound or ultraviolet absorber and to add the masterbatch to a polyolefin resin. For example, Patent Document 8 discloses a masterbatch in which a hindered amine compound having a melting point of 80° C. or lower is incorporated at a high concentration.